Polypodiopsida Cronquist, Takht. & Zimmerm. 1966

Ferns

This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

What is the Name of this Clade?

Polypodiopsida historically did not include the horsetails or whiskferns, two clades now believed to fall within the ferns. The use of other potential names for this inclusive clade, such as Monilophyta or Moniliformopses, is complicated by the uncertain placement of extinct taxa; these clades may not correspond perfectly with the ferns as here defined.

Another set of names, including Pteridophyta and "pteridophyte," is inappropriate for a different reason. These names are commonly used to refer to all seed-free vascular plants, and thus include both the ferns and the lycophytes (Lycopodiopsida). While these two groups have some life-cycle similarities, they are not closely related. Ferns are more closely related to seed plants ("Spermatopsida"--the gymnosperms and angiosperms) than they are to lycophytes (see the Embryophytes page for the phylogenetic tree linking these taxa).

Each ToL branch page provides a synopsis of the characteristics of
a group of organisms representing a branch of the Tree of Life. The
major distinction between a branch and a leaf of
the Tree of Life is that each branch can be further subdivided into
descendent branches, that is, subgroups representing distinct genetic
lineages.